He said it may be that the jury felt identifying such contributory factor as the lack of a school rule might "dilute the stark reality" of what Cornick did.

Summing up the evidence, Mr McLoughlin said the devastation caused by Mrs Maguire's murder on her family had been "self-evident".

The coroner said "the cruelty is unspeakable" as he reminded the court that Mrs Maguire had adopted her sister's two sons after her death.

He said these two men had now lost both their natural and adopted mothers.

Mrs Maguire's husband, Don, told the jury last week how he simply wanted all the evidence to be examined in detail.

Mr Maguire said that this had not happened because there had been no crown court trial, as Cornick pleaded guilty, and no serious case review.

He also criticised the Learning Lessons review carried out in the wake of the tragedy by the Leeds Safeguarding Children Board.

The company director said the "narrative" that there was nothing in Cornick's actions before the attack that could have warned anyone about what he was about to do needed to be challenged so lessons could be learned for the future.